add_subdirectory(recall_combination)
add_subdirectory(recall_palindrome)
add_subdirectory(recall_restore_ip_address)
add_subdirectory(recall_subsets)
add_subdirectory(recall_subsets_2)
add_subdirectory(recall_inc_subseq)
add_subdirectory(recall_permutations)
add_subdirectory(recall_permutations_2)
add_subdirectory(recall_reconstruct)
add_subdirectory(recall_nqueens)
add_subdirectory(recall_suduku)